You might have them double check that info, the axles on the XTZ's are 3 different axles: 1502-348 for Left Front, 1502-347 for Right Front, 1502-562 Both Rear.
The 2009 XTX and XT use 1502-347 for Left Front (reverse of XTZ), 1502-348 for Right Front. The XTX uses 1502-347 for Both Rear while the XT uses 1502-346 for Both Rears.
So you can see, for an XTZ, you would need 3 different axles just on the 2009 , the XTX uses 2 different axles and the XT uses 3 different axles. But within the same series (ie:XTZ, XTX, XT), they use the same.
The 07's and 08's take different axles again.
But I've never heard anything that says that within any series that there is 3 sizes of axle other than the above.